MOSCOW, Jan. 17 (Xinhua) -- Moscow and Damascus believed no one could undermine the peace conference on Syria scheduled for later this month, Russian Foreign Minister Sergei Lavrov said Friday.

Speaking to reporters after his talks with visiting Syrian counterpart Walid al-Moallem, Lavrov expressed Moscow's concern Syrian opposition group the National Coalition might attempt to delay the peace conference, known as Geneva-II, due to internal arguments.

"This goes beyond any reasonable (behavior)," he said.

Moscow was also worried the opposition still had not received a formal invitation to attend the conference, Lavrov said.

Meanwhile, Lavrov said he believed Damascus would demonstrate political will and restraint and would not let anyone undermine the conference scheduled for Jan. 22 in Montreux, Switzerland.

Al-Moallem confirmed the Syrian government would not let the conference be undermined, and accused the United States of supporting terrorist groups operating in Syria.

"How may the U.S. condemn terrorism in Iraq, while supporting the same terrorists in Syria. This is an anti-Syrian conspiracy," al-Moallem said.